1. Field of the Invention
The present invention relates to a bank note processing machine having a function of discriminating the bank note types and the genuineness/falsehood of bank notes, and more particularly to a compact bank note processing machine in which a compact discrimination sensor for irradiating bank notes with light having a plurality of wavelengths in the form of slits is provided such that the entire region of bank notes transported therethrough can be scanned to discriminate the bank note types and genuineness/falsehood of the bank notes based on light transmitted or reflected by the bank notes.
2. Description of the Prior Art
Various bank note processing machines (bank note discriminators) having a discriminating function for discriminating the bank note types and genuineness/falsehood of bank notes have been proposed including, for example, that disclosed in Japanese Patent Application Laid-open No. 312480/1998.
In the bank note processing machine disclosed in the above-cited publication, as shown in FIG. 1, a red LED array 102a and an infrared LED (Light Emitting Diode) array 102b are disposed in parallel to form a light source on one side of a transport path of a bank note 100, and a linear image sensor as a light receiving section 101 is formed on the other side opposite thereto to sandwich the same path. The red LED array 102a and infrared LED array 102b have a length that is substantially equal to the width of the bank note 100 passing by them. The output of the light receiving section 101 is inputted to a bank note genuineness/falsehood discrimination process section 104 to discriminate the genuineness/falsehood of the bank note 100. The reason for the use of the light source having a plurality of wavelengths is that there is a difference between the wavelengths of beams of light transmitted by a genuine bank note and a counterfeit bank note that is a color copy and the genuineness/falsehood can be determined based on the a difference between ratios of transmittance.
In the above-described conventional bank note processing machine, since the plurality of LED arrays 102a and 102b are disposed in parallel to form a discrimination sensor, the dimension of the light source section of the discrimination sensor inevitably becomes great in the direction in which bank notes are transported. As a result, it is necessary to provide the bank note transport path with a great dimension, which has resulted in a problem in that effort to make the bank note processing machine more compact is hindered. It is considered desirable to discriminate bank notes using a light source having many wavelengths from the viewpoint of improvement of accuracy of discrimination of the bank notes. For example, let us assume that a discrimination sensor is configured by disposing an array of LEDs in four rows having different wavelengths in parallel in order to perform discrimination with a light source having four wavelengths. Then, the sensor occupies considerably large dimensions. The sensor size (length) is increased further when a sensor having a light source with five wavelengths is used.
The present invention has been made in view of the above-described situation, and it is an object of the present invention to provide a bank note processing machine in which a discrimination sensor can be formed with a compact size even when bank notes are discriminated using a light source having a plurality of wavelengths and in which a bank note transport path is made short to achieve compactness.
The present invention relates to a bank note processing machine in which bank notes placed on a insert tray are sequentially delivered one by one to be fed to a discrimination sensor section; the bank note types and the genuineness/falsehood of said bank notes are discriminated based on signals detected by a discrimination sensor at said discrimination sensor section; and said discriminated bank notes are sent to an accumulating section, and the above-described object of the present invention is achieved by forming said discrimination sensor with a light projecting section for irradiating the substantially entire passing width of said bank notes in the form of slits and a light receiving section constituted by a photodiode array, forming said light projecting section with a light guide plate and at least one LED provided on a side of said light guide plate and providing said light projecting section and light receiving section in a face-to-face relationship with a transport path of said bank notes sandwiched therebetween or providing them in parallel on one side of said transport path.
Further, the above-described object is achieved by: forming said discrimination sensor with a light projecting section for irradiating over a slit area substantially the entire passing width of said bank notes and a light receiving section constituted by a photodiode array, forming said light projecting section with a light guide plate and an infrared light LED, a red light LED, a green light LED, and a blue light LED provided on a side of said light guide plate, and providing said light projecting section and light receiving section in a face-to-face relationship with a transport path of said bank notes sandwiched therebetween; or disposing a pair of light projecting and receiving sections with a transport path of said bank notes sandwiched therebetween, forming said light projecting and receiving sections with a light guide plate for irradiating substantially the entire passing width of said bank notes over a slit area, an infrared light LED, a red light LED, a green light LED, and a blue light LED provided on a side of said light guide plate, and a photodiode array disposed in parallel with said light guide plate, and detecting information on the top and bottom of the same part of said bank notes passing through said transport path simultaneously with said pair of light projecting and receiving sections using reflected light; or disposing a light projecting section and a light projecting and receiving section with a transport path of said bank notes sandwiched therebetween, forming said light projecting section with a first light guide plate for irradiating over a slit area substantially the entire passing width of said bank notes and an ultraviolet light LED, an infrared light LED, and a first green light LED provided on a side of said first light guide plate, forming said light projecting and receiving section with a second light guide plate for irradiating over a slit area substantially the entire passing width of said bank notes, a red light LED, a second green light LED, and a blue light LED provided on a side of said second light guide plate, and a photodiode array disposed in parallel with said second light guide plate; and detecting information on the top and bottom of the same part of said bank notes passing through said transport path with said photodiode array using reflected light and transmitted light; or disposing a light projecting section and a light projecting and receiving section with a transport path of said bank notes sandwiched therebetween, forming said light projecting section with a first light guide plate for irradiating over a slit area substantially the entire passing width of said bank notes, an infrared light LED and a first green light LED provided on a side of said first light guide plate, and a first ultraviolet light LED array disposed in parallel with said first light guide plate, forming said light projecting and receiving section with a second light guide plate for irradiating over a slit area substantially the entire passing width of said bank notes, a red light LED, a second green light LED, and a blue light LED provided on a side of said second light guide plate, a second ultraviolet light LED array disposed in parallel with said second light guide plate, and a photodiode array disposed in parallel with said second light guide plate, and detecting information on the top and bottom of the same part of said bank notes passing through said transport path with said photodiode array using reflected light and transmitted light. A UV lamp or a barrier discharge fluorescent lamp may be used instead of said first ultraviolet light LED array and second ultraviolet light LED array.
Further, the above-described object is achieved by disposing a light projecting section and a light projecting and receiving section with a transport path of said bank notes sandwiched therebetween; forming said light projecting section with a first light guide plate for irradiating over a slit area substantially the entire passing width of said bank notes and an infrared light LED and a first green light LED provided on a side of said first light guide plate, forming said light projecting and receiving section with a second light guide plate for irradiating over a slit area substantially the entire passing width of said bank notes, a red light LED, a second green light LED, and a blue light LED provided on a side of said second light guide plate, and a photodiode array disposed in parallel with said second light guide plate, and detecting information on the top and bottom of the same part of said bank notes passing through said transport path with said photodiode array using reflected light and transmitted light.
A display section may be provided integrally with or separately from said bank note processing machine to irradiate said bank notes with ultraviolet light from said light projecting section or light projecting and receiving section, thereby displaying images of said bank notes on said display section based on fluorescent light that is visible light generated as a result of transmission or reflection of said ultraviolet light at least when said bank notes react to said ultraviolet light; images of said bank notes may be displayed on said display section based on reflected light or transmitted light of infrared light obtained by irradiating said bank notes with said infrared light from said light projecting section or light projecting and receiving section; and said accumulating section may be a single accumulating section.